John bought one book and paid the price marked inside the bo
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09 Aug 2023, 18:36
Given , Total Selling price = Marked Price + 9%of Marked Price (Sales tax as per the question)
if we let the Marked price be x, we can set up a equation based on the constraints given:
20>x+9x/100>15 (the Total sale price will always be less than 20$ since John received a certain amount as change, and the Total sale price should be greater than 15 , since the exact change was less than 5$)
Thus, 20>1.09x>15 --> 20/1.09>x>15/1.09 --> 18.35>x>13.76
Now let us look at the answer choices:
A. The marked price of the book was more than $13.50 - the option looks correct since lower bound value of x (MP) > 13.76
B. The marked price of the book was less than $18.50 - the option looks correct since upper bound value of x (MP) <18.35
C. The sales tax on the book was less than $1.50. - Sales tax is 9% of x i.e. 18.35*0.09>x*0.09>13.76*0.09
i.e. 1.65>0.09x>0.41 --> so option C is incorrect since our upper bound value is greater than 1.50$
Answers A and B